Sanding or rubbing machine



April l, 1947.

A. c. BURLEIGH SANDING OR RUBBING MACHNE Filed May l, 1945 2 Sheets-Sheet l April 1, l947- A. BURLEIGH 2,418,246

SANDING OR RUBBING MACHINE Filed May 1, 1945 2 sheets-sheet 2 g4 :s as 24- ab) ze [13 lll/ l 15 l1 ,r 1 //f//` I5 Jzraz l 4 .s1 Amm @.Bwfefjh I? 3j L f l I I I l l l u Www/www4 Patented Apr. l, 1947 UNITED N STATES PATENT OFFICE:

2,418,246 v I y n3;

Application May 1, lisslilolo. 591,333

6 Claims.

This invention relates to manually manipulated sanding machines ol the type in which the sanding pad has a gyratory motion, and a counterweight, also having a gyratory motion, is employed to neutralize or balance out the vibration caused by the rapid gyratory motion of the sandine pad.

One of the objects of the invention is to provide a vsanding machine of this type which is relatively simple in its construction and comprises relatively few parts.

Another object of the invention is to provide a sanding machine of this type in which the sanding pad assembly and the counterweight are both mounted on and operated from a single drive shaft.

A further object of the invention is to provide a sanding machine of this type in which the single drive shaft is provided with two eccentric portions situated at 180 apart and on which the sanding pad assembly and counterweight are mounted.

A still further object 'of the invention is to provide a sanding machine of this type having simple and improved means for holding the sanding pad assembly and counterweight from rotation about their axes during their gyratory motion.

Still further objects of the invention are to improve generally sanding machines in the various particulars hereinafter set forth.

In the drawings wherein I have illustrated a selected embodiment of my invention,

Fig. l is a vertical sectional view through a sanding machine embodying the invention.

` Fig. 2 is a partial sectional view taken at right angles to Fig. 1. I

Fig. 3 is a section on the line 3 3, Fig. 1. Fig. 4 is a section on the line 4 4, Fig. 3.

Fig. 5 is a sectional view similar to Fig. 4 but showing the parts in different position.

Fig. 6 is a section on the line 6 6, Fig. 4. The machine herein illustrated comprises a head I in which is journaled a vertically arranged drive shaft 2. said shaft being mounted in bearings 3 and 4 carried by the head. The drive shaft 2 is herein shown as being driven from a suitable motor 5 which is mounted on the head I, the motor shaft 6 being connected by a bevel pinion 1 to a bevel gear 3 fast on the drive shaft 2. The drive shaft 2 is formed with two crank or eccentric portions 9 and I0, said crank portions being 180 apart. The crank portion I0 is provided for by mounting a collar II-on the lower end of the crankportion 9, which collar has formed integral therewith the crank portion I0.

The sanding pad assembly, presently to be described, is mounted on the crank portion 9 while a counterweight element is mounted on the crank portion Ill.

The sanding pad assembly comprises the sanding pad element I2 which may be of any suitable or usual construction, a drive plate I3 which is mounted on the crank portion 9 through the medium of ball bearings I4, and means for connecting the sanding pad I2 to the drive plate I3. This means is herein shown as comprising two leg members I5 which are secured tothe ends of the drive plate I3 and to the bottom ofwhich is secured a supporting plate I6 to which the sanding pad I2 is detachably secured in any approved way. The bearing I4 for the drive plate I3 is situated centrally of said plate and therefore, the rotation of the drive shaft 2 will operate through the crank portion 9 to give the drive plate I3 and the sanding pad I2 connected thereto a gyratory motion.

The rotation of the drive shaft 2 will, there fore produce a gyratory or orbital motion of both the sanding pad assembly and the counterweight I1, said gyratory or orbital motions being in the same orbital direction but out of phase.

With this arrangement the tangential movement of either the sanding pad assembly or the counterweight is, at any instant, in a direction opposite to that of the other. Or stated in another way, the movement of the sanding pad assembly in the direction of either the length or the width thereof will always be in a direction opposite to that of the counterweight. As a result the counter-weight will neutralize or balance out any vibration caused by the gyratory motion of the sanding pad assembly,

Since the sanding pad assembly, including the drive plate I3, is centrally mounted on the crank,

portion 9, it is desirable to provide some means for preventing said sanding pad assembly from turning on its axis during its gyratory motion, and

the same is true with regard`to`the counterweight I1.

I have herein provided for this byemploying Ia stationary guide plate 2| which is interposed between the drive plate I3 and the counterweight, said guide plate 2| being secured at its opposite edges by suitable screws 22 to flanges 23 with` which the head I is provided. The guide plate 2| is provided with a plurality of circular openings 24, in each of which is received the lower end of a pin 25 depending from the drive plate I3 and also the upper end of a pin 26 rising from the counterweight I1. The pins 25, 26 each have a. diameter one-half that of the opening 24, and each opening 2B has a diameter twice the throw of each crank portion 9 or I0. During the gyratory motion of the drive' plate I3 and the counterweight I1, the pins 25, 26 in each opening 24 will revolve around each other. Said openings and pins thus hold both the drive-plate I3 and counterweight I 1 from turning about their axes during the gyratory motion.

3i indicates a housing member which is secured to the underside of the guide plate 2| and which encloses the counterweight I 1.

`It will be observed that with my invention, the desired gyratory motion of the sanding pad as sembly as Well as that of the counterweight is secured through the medium of a single crank shaft and with relatively few moving parts.

It will also be observed that the counterweight I1 is located between the drive plate I3 and the sanding pad I2. This places said counterweight in a. position relatively near the center of gravity of the sanding pad assembly, which comprises the drive plate I3, the supporting legs I5, the plate I6 and the sanding pad I2. An advantage resulting from having the .counterweight located relatively near the center of gravityof the sanding pad assembly is that a better dynamic balance is obtained than if the counterweight were located considerably above or below such center of .gravity.

I will preferably make the supporting plate I6 of some suitable insulating material so that the sanding pad I2 will be insulated from the head I. This will prevent any leakage of current from the motor through the head to the work when the pad I2 is being used for a web rubbing or abrasive operation. g

While I have herein referred to the machine as a sanding machine and have referred to the pad I2 as a sanding pad, yet I wish to state that the word sanding has been used in a generic sense to indicate any abrasive or rubbing action which would also include a polishing action. The character of the operation performed by the machine, that is, whether it performs an abrasive operation or a rubbing or polishing operation depends upc-n the character of the active l surface of the pad I2. 'I'his surface may be such as to produce an abrasive action or it may be a relatively soft surface which will `produce a rubbing or polishing action. It will be observed that the character of the surface of the pad I2 does not in any way affect the invention.

My invention, therefore, provides a portable machine for sanding, abrading, rubbing or polishing any surface, which machine is not only simple in construction and comprises relatively few parts but which also is Well balanced and operates free from undesirable vibration.

I claim:

1. A machine of the class described comprising a head member, a driving shaft rotatably supported thereby and having two oppositely disposed crank portions, a pad-carrying element mounted on one crank portion, an operating pad secured to said pad-carrying element, said pad providing the entire abrading or rubbing surface of the machine, a counterweight mounted on the other crank portion and means to rotate said driving shaft, both the pad-carrying element and the counterweight being free to have a bodily gyratory motion about the axis of the driving shaft-as the latter is rotated with the tangential movement of each always in an opposite direction to that of the other.

2. A machine as in claim 1, provided with means common to both the padcarrying element and the counterweight to prevent each fromk turning about its axis during its gyratory motion. 10

ing a stationary guide plate situated between theY 3. A machine s uch as described in claim 1, havpad-carrying element and the counterweight and provided with circular apertures, and pins carried by both the pad-carrying element and the counterweight and extending into said apertures.

4. A machine of the class described comprising a head member, a driving shaft rotatably supported thereby and having two oppositely dis- ;posed crank portions, aj. pad-carrying elementmounted on one crank portion. an operating pad secured to said pad-carrying element, a couniierweight mounted on the other crank portion, means to rotate the driving shaft thereby to give both the pad-carrying element and the counterweight a gyratory motiony about the axisoi' the driving shaft, and a stationary guide plate carried by the head member andsituated between said crank portions, both theV pad-carrying element and the counterweight having means co-operating with said stationary guide plate to prevent them from turning about their axes during their and situated between the supporting plate and the driving plate, and means to rotatethe driving shaft.

6. A machine of the class described comprising a. head member, a driving shaft rotatably supported thereby and having two oppositely disposed crank portions, a driving plate mounted on one crank portion, leg members depending from saidV driving plate, a supporting plate secured to the lower ends of the leg members, an operating pad `carried by said supporting plate, a counterweight carried by the other crank portion and situated between 'the supporting Aplate and the driving plate, means to rotate the driving shaft thereby to give both the driving plate and the counterweight a gyratory motion, a stationary guide-plate situated between the drive plate and the counterweight, and means co-operating with said guide plate to prevent both the drive plate and the counterweight from rotating about their axes during their gyratory motion. ARTHUR C. BURI..EIGH.I

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

